MICRO IRRIGATION PRACTICES IN TOMATO - Management, Performance, and Applications of Micro Irrigation Systems - page 187

15.2 MATERIALS AND METHODS
During the two-year period (2006 and 2007), field experiments were conducted at
the Regional Research and Technology Transfer Station in Chiplima, which comes
under the West Central Table Land Zone of Odisha - India. The latitude, longitude
and altitude for the site are 20 0 21'N, 80 0 55' E and 178.8 m above the mean sea level,
respectively. The area falls under the subhumid climatic condition in the eastern part
of India. The total rainfall in the study area during the crop growing season (8th Jan
to 3rd April) was 32.0 mm for 2006 and 29.0 mm for 2007, respectively. The mean
daily air temperature during the crop growing period ranged from 15.4 °C to 31.3 °C
during 2006 and 16.8 °C to 29.97 °C during 2007, respectively. The mean daily rela-
tive humidity ranged from 45.5% to 689.7% in 2006 and 47.2% to 70.5% in 2007,
respectively.
The soil texture of the study area is sandy loam with sand, silt and clay percent-
age of 78.8, 10.8 and 10.4, respectively. Average values of bulk density, volumetric
moisture content at fi eld capacity and permanent welting point are 1.55 gm/cc, 26%
and 10%, respectively. Average pH, EC and organic carbon were 6.3, 0.09 dS/m and
0.51%, respectively.
Tomato variety Arjun was planted in the plots with 75 cm spacing from row to row
and 60 cm from plant to plant. Plantations (25 days seedlings) were transplanted on
8th Jan of each of the two years and harvested on 3rd April for both the years. Appli-
cations of N, P and K fertilizers were 150, 100 and 100 kg/ha, respectively. Nitrogen
was applied 50% as preplating and rest 50% as top-dressing one month after planting.
Phosphate and potash fertilizers were applied 100% as preplanting each. All preplant-
ing fertilizers were applied in pits whereas top dressing fertilizers were applied as ring
placement in all the plots. Other cultural practices of the crop were followed as per
recommendations by Indian Council of Agricultural Research - New Delhi [21].
The LDPE (low density poly ethylene) fi lm of 50-micron thickness was used for
mulching around the plant. The lateral lines of 12 mm diameter LDPE pipes were
laid along the crop rows and each lateral served one row of crop. The laterals were
provided with on-line emitters of 4 L/hr. discharge capacity. LDPE pipes of 75 mm
diameter were used for main and 63 mm diameter was used for submain. The main
line was directly connected to a 1.5 HP submersible pump installed to lift water from
an open sump. The manifold unit was connected with a screen fi lter, a pressure gauge
and control valve. The duration of delivery of water to each treatment was controlled
with the help of gate valve provided at the inlet end of each lateral. In case of furrow
irrigation, irrigation was scheduled at weekly interval.
The experiment was laid out in randomized block design having eight treatments
and replicated thrice with a plot size of 6 m × 3 m. Each treatment was spaced 0.5 m
apart to avoid overlapping of treatments (Fig. 1). The treatments were:
T1 = 100% irrigation requirement (IR) through drip irrigation (VD);
T2 = 80% IR through drip irrigation (0.8 VD);
T3 =60% IR through drip irrigation (0.6 VD);
T4 = 100% IR by furrow irrigation (V);
T5 = 100% IR through drip irrigation with black LDPE mulch (VD+M);